58 New Motors. [January, 



is stated by tlie inventor to be twelve or fifteen times the original 

 volume of the gases, so that tbe power obtained from a small volume of 

 gas is very great. We bad no means of knowing the amount of pressure 

 on the piston, but Dr. Drake informed us tbat the engine could work 

 up to the power of twenty horses. It is a little more bulky than a 

 steam engine of the same power. 



" This engine can be set in operation in a few seconds when there is a 

 supply of gas, which can always be had by keeping it ready made in 

 a reservoir. In this one respect it has an advantage over steam. By 

 the perfect combustion of fuel under a steam boiler, and under retorts 

 to generate the gas, the expense of the two — gas and steam — may not 

 diflfer much, to be used as motive agents ; but there are great advanta- 

 ges on the side of steam. The jDrocess of obtaining steam is more simple 

 than generating gas, and consequently cheaper. The construction of the 

 steam engine is also more simple, and so are most of its appendages. 

 The action of the steam on the piston is altogether superior to that of 

 an explosive mixture. Steam is rapid in its motion, silent, elastic, and 

 equable in its pressure, making the piston move without jarring and 

 noise. The explosive gas operates like small discharges of artillery ; it 

 expends much of its force suddedly on the cylinder heads, and shakes 

 the whole machinery with great violence. This is a difficulty which can 

 not be overcome ; it belongs to its very nature, and its continued use in 

 a large engine would soon shake it to pieces. For these reasons we 

 conclude that this new motor will never supersede the steam engine ; but 

 we entertain great respect for the sincerity, the ingenuity, the perseve- 

 rance, urbanity, and intelligence of its inventor." 



To which Dr. Drake replies thus : 



" Messrs. Editors — Will you grant me a small space in your valuable 

 journal, to remark that the percussive action of explosive mixtures of 

 gas and atmospheric air, when fired in a properly constructed engine, is 

 not of that injurious character you suppose, much of the jar in the 

 working of the machine you saw being the result of a sudden and violent 

 shutting of the valves at the moment of ignition — a fault which will be 

 remedied by the use of larger and better arranged ones. This has been 

 demonstrated. 



" You have overlooked also the a^ity of using as fuel the ligidd 

 hydro-carbons, as turpentine, naphtha, oil of tar, etc., the vapors being 

 generated by the escape heat. The use of these products as fuel enables 

 us to dispense with the gas, and the space they would occupy would not 

 be more than one-tic elf tli of that required for coals. 



" There being no boiler, there is much economy in the first cost of an 



